Jack Burnell led the British athletes in the 10km open water race at the European Championships in Berlin.
The British Gas National Centre Loughborough swimmer had a strong race but was unable to hold on to third place going into the last 200m and finished sixth in 1:50:04.1.
Burnell said: “I am very happy with the way I swam the race. Tactically it went really well and I was pleased with how I executed a lot of the points we had discussed prior to the race.
“Unfortunately, although I went into the second-to-last buoy in third, I lost my positioning after being held back which meant I finished sixth.
"Although I’m disappointed not to have won a medal, there are a lot of positives I can take from this race and I'm looking forward to the 5km Team event on Saturday."
Tom Allen (City of Swansea Aquatics) finished 14th in 1:50:12.5 and Caleb Hughes (Hatfield) was 24th in 1:50:56.7.
In the women’s 5km time trial Alice Dearing (Royal Wolverhampton) finished in 16th (1:01:50.9) and Lucinda Campbell (Windsor) was 19th (1:03:12.7).